The galileo or gal is the CGS unit of acceleration. The galileo is defined as 1 centimetre per second per second. The symbol of the galileo is Gal.

In SI units, one galileo equals 1/100 metre per second squared = 0.01 ms⁻².

The acceleration due to gravity at the Earth's surface is approximately 980 Gal. Variations in gravitational acceleration, such as may be due to mountains or masses of lesser density within the Earth's crust, are typically tens to hundreds of milligalileos (mGal).

The galileo is named after Galileo Galilei, a physicist who made the first measurements of the acceleration due to gravity.